[1][2] Most of the time, sinus tarsi syndrome onsets after ankle sprains, however there can be other causes.

[3] More rarely, excessive physical activity and other forms of foot trauma/chronic ankle injury are thought to be the cause.

[1][6] In the case of posterior tibial tendon dysfunction causing flatfoot, sinus tarsi syndrome can also develop due to the disruption in the entire structure of the foot.

Occasionally, peroneal spasms, valgus hindfoot, and limited varus motion can also be present.

Diagnosis is often a process of elimination as sinus tarsi syndrome is rarely a definitive disorder.

[3] In cases of flatfoot, sinus tarsi syndrome is complicated by the collapse of the arches.

In these cases, surgery includes debridement (cleaning out) of the sinus tarsi and possible reconstruction of the foot.

Untreated sinus tarsi syndrome can develop into chronic ankle pain and disability.